1. Technical Field
The present invention relates to a circuit for a physical quantity detection device, a physical quantity detection device, an electronic apparatus, and a moving object.
2. Related Art
There is a known physical quantity detection device that detects a physical quantity, such as angular velocity and acceleration, by using an vibrator, such as a quartz vibrator (piezoelectric vibrator) and an MEMS (micro electromechanical systems) vibrator.
In an angular velocity detection device, for example, in which the frequency at which an vibrator is driven and the frequency at which angular velocity is detected typically differ from each other, when a detection signal outputted from the vibrator is detected by using a drive signal, a detuning frequency component formed of a detuning frequency, which is the difference between the drive frequency and the detection frequency, is produced as an undesired wave. When the detuning frequency component increases, for example, because an impact having a large magnitude acts on the angular velocity detection device, saturation occurs in a downstream amplification circuit, resulting in an incorrect output result in some cases.
JP-A-2008-256668 discloses an angular velocity sensor including a noise remover that includes an active filter and removes a detuning frequency component from a signal having undergone synchronous detection in a synchronous detector.
In the configuration disclosed in JP-A-2008-256668, in which the active filter is provided in a position upstream of an amplifier, noise resulting from a transistor in the active filter is produced in a portion upstream of the amplifier. As a result, the noise produced in the active filter is undesirably amplified by the amplifier and outputted.